1. Field of the Invention
This invention relates to a substrate processing apparatus and substrate processing method for removing, utilizing a processing liquid, adhesives such as resist, polymers, etc., which adhere to the substrate during the process of the substrate, such as semiconductor device manufacturing process.
2. Description of the Related Art
Recently, in the process of manufacturing semiconductor devices, the miniaturization of design rules has rapidly progressed. Along with this has come the use of a low-dielectric-constant organic film as an interlayer insulating film called low-k film, and the use of Cu having low electrical resistance as a wiring-layer material instead of Al, in view of the high speed operation of the semiconductor devices.
Dual damascene process has been utilized to form Cu wiring layers with the interlayer insulating film being arranged between the adjacent Cu wiring layers. The dual damascene process, for example, is carried out in the following order. A stop layer is formed on the already-formed Cu wiring layer in the damascene structure of the under level, and on the stop layer a low-k interlayer insulating film is formed. On the interlayer insulating film, a resist film is formed according to a predetermined pattern. Via-etching is carried out by using the resist film as a mask. Then, after the resist film and the polymers in the hole are removed, a sacrifice layer is formed. Once again, a resist film with a specific pattern is formed on the interlayer insulating film, and trench etch is carried out by using the resist film as a mask. Then the resist and polymers in the hole are removed. Then, after the sacrifice layer and the stopper layer are removed by etching, a top Cu wiring or a plug is formed.
The removal of the aforementioned resist and polymers is conducted by performing wet cleaning after dry ashing. This is because, it is not possible, until now, to completely remove the resist and the polymer only through the application of wet cleaning, utilizing a processing liquid.
However, when dry ashing is conducted at the step of removing resist after the manner of pattern processing, damage is done to the low-k film that is the interlayer insulating film, causing a variety of problems with integration with the Cu wiring.